Noob XC204 Derailleur Question...

Hey all, so I got my bike today and am attempting to put it together myself to help me learn more about the bike. The build consisted of installing seat post, handlebars, wheels, rear wheel, rear derailleur and pedals... not that much really.

Unfortunately I'm stuck on the rear derailleur. It doesn't make sense to me as to how it attaches to the swing arm. There is a loose washer/nut thing in the area circled below, and I assume that is what should hold the derailleur to the frame, but can't figure out how. Any advice would be much appreciated!

Thanks for the response. Looking at it, it doesn't appear to have threads that would essentially create a 'front' and 'back' of the bolt.

Taking a look at it, it almost appears as though the inside of the bolt is two piece...

It looks to me like its all there, screwed together. One side should be a allen wrench bolt and the other should look like a big flat screw driver will fit in a slot on the back. This picture shows the slot on the back. Hold the back and try unscrewing it.

Was it all there or did you have to buy something? My curiosity is making me ask.

Yeah it was all there, just a two piece bolt that required a hex wrench and nut driver... I'm a bit ashamed I couldn't figure it out myself. I installed a superchager on my Mustang, but couldn't mount a derailleur to my bike frame. :-)